1. Field of the Invention
The present invention relates to a mobile terminal which can connect and communicate with a plurality of different types of radio communication stations, a resource allocation manager for switching radio communication stations which connect and communicate with a mobile terminal and manage the allocation of the resource, and a communication control method for controlling connection and communication with a mobile terminal and a plurality of different types of radio communication stations.
2. Related Background Art
Recently there are radio communication spots where a plurality of radio communication networks, such as a cellular network (that is a cellular telephone communication network) and a radio LAN network (that is a radio LAN communication network), are overlapped and allocated to a same area. For Such a radio communication spot, technologies for a mobile terminal having interfaces which can connect and communicate with each radio communication station of the plurality of radio communication networks to switch the interface to use according to the surrounding communication conditions have been proposed or commercialized.
In the case of an access network selection method disclosed in Japanese Patent Application Laid-Open No. 2005-277815, for example, a mobile information terminal that can connect and communicate with a plurality of communication networks detects the deterioration of the receiving status of another communication network during communication, and controls such as switching to another communication network so as to continue the communication if the receiving status of the accessing communication network deteriorates
Another example is an information processing device disclosed in Japanese Patent Application Laid-open No. 2005-176021, which selects a communication profile to be used for a radio LAN based on the surrounding communication conditions, and automatically switches to the best communication environment under the communication status desired by the user.
Another example is a service called “BT Fusion®”, provided by BT in the United Kingdom, to meet the increasing demand for communication using a fixed telephone network of which the communication charge is cheaper than a cellular network This service allows a mobile terminal accessing a cellular network outdoors, such as outside the home, to use a fixed telephone network indoors, such as at home, by switching access to the fixed telephone network using Bluetooth®.
Today bidirectional real-time communication, such as voice communication and TV telephone, using not a cellular network but a communication network such as a radio LAN network, is actively performed This real-time communication, using a radio LAN network and so on, is implemented by the improvement of VoIP (Voice over Internet Protocol) technology.
In this case, a mobile terminal having a plurality of radio interfaces, which can connect and communicate with a cellular network and a radio LAN network, requires high power consumption during standby time compared with a mobile terminal having a single radio interface For example, in “N900iL”, which is one FOMA® model of third generation portable telephone terminals, a continuous standby time in FOMA single mode (that is, a mode in which only FOMA is activated and used during standby time) is approximately 350 hours in static time, but in DUAL mode (that is, a mode in which both FOMA and radio LAN are activated and used during standby time), a continuous standby time is approximately 150 hours in static time, which is much shorter.